I've been to Italy and France with Club C, there buses aint as good, neither is there accom, but apart from that i had no issues with them. However, their accom for smaller groups (just the two of us) is pretty woeful at CM, at least in France they had those lovely Diamond lodges for us.
Siesta are the biggest of the companies, and you never really get any bargains with them at the last minute, although years ago when my wife had fixed holidays (last two weeks in July .... nedtastic!

) i used to book last min stuff with them and could usually pick something up. My beef with Siesta wasn't the reps, but when i did go with them i have to say my experience with them wasn't good, they were pretty hopeful ... however, you find that attitude in all companies i guess!
Never ever took the free bus, i'll walk everywhere when i can